Physical fitness and various forms of exercise ave increased considerably in popularity in recent years, as has the use of various devices permitting exercise in a confined area such as in a seperate room of a dwelling or in a gymnasium. Various forms of outdoor exercise also have increased in popularity, and in particular cross-country skiing. Cross-country skiing has been determined to be one of the most effective forms of exercise, both as a cardiovascular fitness exercise and for simultaneously exercising nearly every major muscle group in the body, without subjecting the body to the constant jarring and possibility of injury which sometimes results from other types of exercise. However, due to the limited time periods during which cross-country skiing can be carried out, that is, when there is adequate snow on the ground, individuals wish to be in shape for skiing as soon as there is adequate snow. Also, other individuals wish to derive the physical benefits from an exercise which closely simulates cross-country skiing without actually performing the skiing in the outdoor environment.
Various devices have been developed for indoor exercise which provide both the cardiovascular and muscular development as provided by cross-country skiing, and which simulate cross-country skiing for those who wish to develop the muscle control and stamina for performing the same during the off-season or for obtaining the physical benefits attendant thereto. Examples of such devices are shown in U.S Pat. Nos. 1,982,843; 3,941,377; 4,023,795; 4,402,506; 4,434,981; 4,529,194; and 4,659,077.
Other types of indoor exercise devices have been developed which simulate downhill-type skiing such as shown in U.S. Pat. Nos. 2,274,081; 3,408,067; 3,455,550; 3,475,021; 3,711,089; 3,729,207; 3,791,645; 3,807,727; 4,092,787; 4,252,312; 4,376,532; and 4,595,195. Still other types of exercise devices such as shown in U.S. Pat. Nos. 1,766,089; 3,332,683; 3,554,541; and 3,711,090 provide a treadmill effect which is beneficial for the leg muscles and cardiovascular fitness, but not the arms and upper body.
Although exercise devices of the type shown in the above-mentioned patents simulating cross-country skiing perform satisfactorily, they require a structure which is relatively expensive, especially when the exerciser is being developed for the home market in contrast to the even more expensive exerciser manufactured for use by commercial establishments such as gymnasiums, health spas, etc.
The closest known prior art to my invention is disclosed in U.S. Pat. No. 4,618,139. However, there are two primary differences between my exerciser and exercise machines of the type as shown in this patent. First, rollers of the present invention which provide movement for the footplates of the ski exerciser are trapped within U-shaped channels formed in elongated rails thereby preventing disengagement of the footplates from the rails whereas in prior devices the wheeled footplates merely roll along the top of the tracks in a manner similar to the wheels of a railcar. A second important difference is the manner in which resistance is applied to the movement of the levers or handles and the footplates, respectively. The ski exerciser of the present invention utilizes a single adjustable resistance mechanism which allows for both combined or independent adjustment of the arm activited levers, while many of the prior art exercise machines use a seperate adjustable clutch assembly for each handle.
Furthermore, the ski exerciser of the present invention utilizes a belt which is connected to each of the footplates and which slidably engages a pair of rods at the front and rear ends of the base frame to provide resistance to the movement of the footplates. The exercise machine of U.S. Pat. No. 4,618,139 uses a complex cable-pulley-clutch assembly to provide resistance to the movement of the footplates. Therefore, there are considerable differences between the ski exerciser of the present invention and the exercise machine disclosed in this patent and in other known prior art devices.
Therefore, the need has existed for an improved exercise device and in particular a device which simulates cross-country skiing, which can be produced economically yet which provides a sturdy, durable and smooth-operating device which achieves the desired physical results as those achieved by cross-country skiing, and which is usable within a protected environment.